"Czech cryptologists Vlastimil Klima, Ondrej Pokorny, and Tomas Rosa
have come up with an extension of the "Bleichenbacher attack" on RSA
with PKCS #1 v1.5 padding as used in SSL 3.0 and TLS 1.0. Their
attack requires the attacker to open millions of SSL/TLS connections
to the server under attack; the server's behaviour when faced with
specially made-up RSA ciphertexts can reveal information that in
effect allows the attacker to perform a single RSA private key
operation on a ciphertext of its choice using the server's RSA key.
Note that the server's RSA key is not compromised in this attack."